Viruses have in the past, and will into the foreseeable future, continue to significantly affect living organisms, whether animal, plant or otherwise. Viruses are perhaps most well known as infectious agents capable of replicating inside eukaryotic or prokaryotic cells. For thousands of years, viruses have caused diseases in epidemic proportion as well as on less dramatic scales. More recently, the possibilities for putting viruses or portions of viruses to use in ways beneficial to living organisms have been uncovered and are expanding. For example, non-virulent viruses are considered a safe and efficient means for delivering DNA molecules to cells. In this regard, there is a demand for purified viruses. Initial virus harvests from culture systems usually contain the virus as part of a complex mixture which includes host proteins and nucleic acids. Traditional means for concentrating and purifying viruses include ultracentrifugation and density gradient separation methods. These methodologies are time-consuming, cumbersome and present potential health hazards. Other procedures, such as polyethylene glycol or ammonium sulfate precipitation, may also lead to the loss of viral infectivity. Due to the difficulties in the current approaches to concentrating and purifying viruses, there is a need in the art for improved methods.
Viral contamination of preparations, such as biologic products, is a serious problem. For example, use of HIV contaminated blood for transfusions has had tragic consequences for the recipients. Potential viral contamination of a biological may arise from the source material or as adventitious agents introduced by the culture process. Due to the difficulties in the current approaches to preparing virus-free preparations, there is a need in the an for improved methods.
The present invention fulfills these needs, and further provides other related advantages.